Don't give up, Kiyoshimo! The Lord Clive-class monitors could do it, and so can you. Heck, the HMS General Wolfe managed to carry 1×18-inch gun, 2×12-inch guns, 2×6-inch (152 mm) guns, and 2×3-inch (76 mm) guns despite being lighter than Ooyodo!
Widen her beam enough for the barbette and magazine to fit as well as lose the tubes but she'll probably be a "heavy" destroyer by that time. hey, at least she's got the offensive firepower of a BB.